This replacement 3.18mm (1/8") collet is used in these micromotor handpieces:
H.MH-170
H.MH-150 with serial numbers 811xxxx and higher (that's serial number 811 plus four more digits)
H.MH-145 H.MH-145A and H.MH-135 discontinued handpieces
H. MH-130 Handpiece used on K.103018 (Item # 10795) Battery Operated Micromotor